title: Role of echocardiography in patients with intravascular hemolysis due to suspected continuous-flow LVAD thrombosis.
abstract: OBJECTIVE
  This study sought to characterize the echocardiographic findings of patients presenting with intravascular hemolysis (IVH) due to suspected continuous-flow left ventricular assist device (LVAD) pump thrombosis.
  
  
  BACKGROUND
  LVAD patients who develop pump thrombosis often present with IVH. Echocardiography may be able to detect device dysfunction in this setting.
  
  
  METHODS
  Continuous-flow LVAD patients presenting with IVH due to suspected pump thrombosis were identified. Patients underwent echocardiography with cannula Doppler flow velocity interrogation. Findings were compared with baseline and follow-up studies, and with 49 stable LVAD control patients.
  
  
  RESULTS
  Of 145 patients, 14 (10%) had IVH due to suspected pump thrombosis. The mean age was 55 ± 15 years, 93% were men, and 50% received LVAD as destination therapy. Mean duration between implantation and IVH was 231 ± 218 days. Eleven (79%) patients presented with hemoglobinuria, 9 (64%) with jaundice, and 5 (36%) with acute heart failure. Reduced cannula diastolic flow velocity and increased systolic/diastolic (S/D) flow velocity ratio were the only echocardiographic parameters significantly different from controls (outflow cannula 0.3 ± 0.2 m/s vs. 0.8 ± 0.3 m/s, p = 0.03, and 5.9 ± 2.8 vs. 1.7 ± 0.7, p < 0.01, respectively), and were worse for IVH patients with acute heart failure compared with those without (outflow cannula 0.2 ± 0.1 m/s vs. 0.5 ± 0.2 m/s, p = 0.04, and 7.2 ± 3.3 vs. 5.3 ± 2.0, p = 0.02, respectively). Outflow cannula diastolic flow velocity and S/D flow velocity ratio changed significantly from baseline (p = 0.01 and p < 0.01, respectively) in IVH patients, whereas systolic flow velocity did not change (p = 0.59). Odds ratios for outflow cannula diastolic flow velocity and S/D flow velocity ratio for predicting IVH were 0.60 (95% confidence interval [CI]: 0.51 to 0.73), p = 0.02, and 2.45 (95% CI: 2.37 to 2.52) p < 0.01, respectively. Corresponding inflow cannula values were similarly significant. Pump thrombosis was confirmed in 7 (50%) patients after LVAD retrieval.
  
  
  CONCLUSIONS
  Reduced cannula diastolic flow velocity and increased S/D flow velocity ratio identified continuous-flow LVAD dysfunction in patients with IVH due to suspected pump thrombosis better than other echocardiographic parameters.
authors.affiliation: Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic, Rochester, Minnesota.
authors.forename: Nowell M
authors.initials: NM
authors.lastname: Fine
authors.forename: Yan
authors.initials: Y
authors.lastname: Topilsky
authors.forename: Jae K
authors.initials: JK
authors.lastname: Oh
authors.forename: Tal
authors.initials: T
authors.lastname: Hasin
authors.forename: Sudhir S
authors.initials: SS
authors.lastname: Kushwaha
authors.forename: Richard C
authors.initials: RC
authors.lastname: Daly
authors.forename: Lyle D
authors.initials: LD
authors.lastname: Joyce
authors.forename: John M
authors.initials: JM
authors.lastname: Stulak
authors.forename: Naveen L
authors.initials: NL
authors.lastname: Pereira
authors.forename: Barry A
authors.initials: BA
authors.lastname: Boilson
authors.forename: Alfredo L
authors.initials: AL
authors.lastname: Clavell
authors.forename: Brooks S
authors.initials: BS
authors.lastname: Edwards
authors.forename: Soon J
authors.initials: SJ
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D003326:Coronary Circulation; D018618:Echocardiography, Doppler, Color; D018619:Echocardiography, Doppler, Pulsed; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D006353:Heart-Assist Devices / Q000009:adverse effects*; D006461:Hemolysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011475:Prosthesis Failure; D012039:Regional Blood Flow; D012189:Retrospective Studies; D013318:Stroke Volume; D013927:Thrombosis / Q000097:blood / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D013997:Time Factors; D016277:Ventricular Function, Left
keywords: BTT; DT; IAS; IVH; IVS; LAP; LVAD; PI; RAP; S/D; bridge to transplantation; destination therapy; echocardiography; interatrial septum; interventricular septum; intravascular hemolysis; left atrial pressure; left ventricular assist device; pulsatility index; pump thrombosis; right atrial pressure; systolic/diastolic